Flameless atomic absorption spectrophotometry and neutron activation analysis have been used for quantitation of Pt, Mg, Ca, Fe and some other elements in biological tissues and fluids. The analyses are important in biochemical, pharmacokinetic and binding studies. Very sensitive analytical techniques are necessary because, in most cases, the sample size is very small as well. Separation techniques including ion-exchange chromatography, solvent extraction and electrophoresis have been used for purification of samples and fractionation and concentration of chemicals prior to analysis and as a means of eliminating substances interfering with trace-level assays. BIBLIOGRAPHIC REFERENCES: Litterst, C.L., Gram, T.E., Dedrick, R.L., LeRoy, A.F. and Guarino, A.M.: Distribution and Disposition of Platinum Following Intravenous Administration of cis-Diamminedichloroplatinum (II) (NSC 119875) to Dogs. Cancer Res. 36:2340-2344, 1976. Ward, J.M., Grabin, M.E., LeRoy, A.F. and Young, D.M.: Modification of the Renal Toxicity of cis-Dichlorodiammineplatinum (II) with Furosemide in Male F344 Rats. Cancer Treat. Rep. 61: 375-379, 1977.